The present invention relates to a sewing machine, and more particularly to a data processor for processing input data entered through a keyboard to produce stitch pattern data used for sequentially stitching letters on materials with a sewing machine.
FIGS. 6(a) and 6(b) show fancy stitches, or three-letter and two-letter marks M3, M2, for initials composed of symbols and alphabetical letters. To form these illustrated stitches, it is desirable to sew an outer symbol or pattern Sd which looks like inequality signs and an outer symbol Ss of a lozenge shape, and also to sew letters or characters C1 through C3 of different fonts or outlines at lefthand, central, and righthand positions between the outer symbols Sd (FIG. 6(a)) or at lefthand and righthand positions within the outer symbol Ss (FIG. 6(b)). By thus producing the stitches, the resultant stitch patterns have appealing designs.
U.S. Pat. Nos. 4,388,883, 4,557,207 and 4,622,907 disclose sewing machines including a data generator which can selectively generate stitch pattern data for alphabetical letters of a desired font or outline. For entering such stitch pattern data, a font code is first entered to select a desired font, and then individual character codes are entered to thereby select desired characters or letters from a group of characters or letters of the selected font.
Specifically, U.S. Pat. No. 4,388,883 discloses a stitch pattern sewing machine provided with a memory in which stored are sewing pattern data representative of a plurality of characters and symbols, such as English letters, Japanese Katakana letters, for each of stitch patterns, together with identification codes for those characters and symbols. With the identification codes, desired stitch pattern data are read out from the memory, and the data thus read our are modified as the case commands, to for example enlarge, reduce or rotate the data. Based on the stitch density and arrangement data for the stitch pattern, sewing data or needle position data for each needle are produced. Thereafter, in timed relation with the vertical movements of the needle, the needle and the workpiece are relatively moved in accordance with the sewing pattern data. To this end, a keyboard is provided for entering the characters, in which keys are changeable between an alphabetical mode and a Japanese character mode for allowing to enter both type of letters. While it may be possible to form a plurality of stitch letters each differing in font, the font of the character is not automatically changed in association with the selection of the character.
Referring to U.S. Pat. Nos. 4,557,207 and 4,622,907, stitch pattern data representative of various fonts and stitch pattern have been stored in advance in a memory on font basis. The operator firstly designates the font area in the memory and then depresses a desired alphabetical key to designate a desired stitch pattern, so that the stitch pattern data representative of the designated font and the designated stitch pattern are read out from the memory. In this manner, a desired stitch pattern is formed, however, in the sewing machine thus arranged, it is necessary to select the font each time when the stitching is performed.
According to the prior art stitch pattern sewing machines, when the operator wants to form characters of different fonts successively as shown in FIGS. 6(a) and 6(b), the operator has to enter both font codes and individual character codes according to the desired alphabetical letters to be stitched. It has been tedious and time-consuming to enter such codes.